/Engine/Plugins/Experimental/GeometryScripting/Source/GeometryScriptingCore/Public/GeometryScript/MeshDecompositionFunctions.h
Extract the triangles identified by Selection from TargetMesh and copy/add them to StoreToSubmesh
static [UDynamicMesh](API\Runtime\GeometryFramework\UDynamicMesh) * CopyMeshSelectionToMesh ( [UDynamicMesh](API\Runtime\GeometryFramework\UDynamicMesh) * TargetMesh, [UDynamicMesh](API\Runtime\GeometryFramework\UDynamicMesh) * StoreToSubmesh, [FGeometryScriptMeshSelection](API\Plugins\GeometryScriptingCore\GeometryScript\FGeometryScriptMeshSelection) Selection, [UDynamicMesh](API\Runtime\GeometryFramework\UDynamicMesh) *& StoreToSubmeshOut, bool bAppendToExisting, bool bPreserveGroupIDs, [UGeometryScriptDebug](API\Plugins\GeometryScriptingCore\GeometryScript\UGeometryScriptDebug) * Debug )